Article handling method and apparatus



Nev. K 1960 S. S. SKUTLE ETAL ARTICLE HANDLING METHOD AND APPARATUS Filed QG'L 21, 195'?" Unite States Patent ARTICLE HANDLING METHOD AND APPARATUS Sebben S. Skutle, 17356 Redmond Woodenville Road, Redmond, Wash, and Roderick ;L. Bulitz, 1338 Morthlk Way, Seattle, Wash.

Filed Oct. 21, 1957, Ser. No. 691,227 8 Claims. (Cl. 214-731 This invention relates to article handling method and apparatus. It pertains particularly to a modified fork truck for use in locating and stacking plywood and fiberboard panels.

Present day building practice and construction requirements demand that the plywood mill and warehouse carry a highly diversified stock. This customarily is racked and stacked in areas reserved for each particular product grade.

Since the racking and stacking customarily are done by a conventional fork truck designed to carry the panels in a crosswise position, an unduly large amount of aisle space must be reserved for maneuvering the truck as required to traverse the aisles and then to turn at right angles in order to deposit its load.

A considerable amount of valuable aisle space obviously could be conserved if it were possible to reserve stacking space only slightly greater than the width of the panels, usually four feet, and then to operate the fork truck in such a manner that it would eject its load sideways into the reserved space without backing and turning. Attempts to achieve this purpose heretofore by placing rollers in the space and pushing the load from the truck onto the rollers have been unsatisfactory first because the rollers themselves occupy a substantial amount of vertical space and of even more importance, the rollers mark and disfigure the panels.

Accordingly it is the general object of this invention to provide method and apparatus for handling articles, particularly for inserting endwise into openings of restricted width elongated heavy articles carried crosswise by a fork truck or other vehicle. Although the method and apparatus are described herein with particular reference to the stacking of plywood panels with a fork truck, it will be apparent that they are applicable to the handling of other articles such as boxes and crates in warehouses, coilins in mausoleums, and the like.

The method and apparatus of our invention are described herein with particular reference to the drawings wherein:

Fig. 1 is a view in perspective of a fork truck embodying our article handling apparatus; and

Fig. 2 is a schematic view of an hydraulic system by means of which the fork truck illustrated in Fig. 1 may be operated.

Generally stated, the presently described method of handling articles comprises placing the article endwise opposite an opening in which it is to be inserted, applying a lifting force to the article at a predetermined point of application, and moving the article endwise in the direction of the opening by a predetermined increment. The article then is lowered to substantially its original plane and the lifting force reapplied at substantially the same point of application as in the first instance after which the article is moved endwise in the direction of first movement by another increment. This sequence is repeated until the article has been substantially fully introduced into the opening.

The apparatus employed for the foregoing sequence broadly comprises means for placing the article endwise opposite an opening into which it is to be introduced, means for applying a lifting force to the article at a predetermined point of application until the article has been lifted from the surface upon which it has been resting, and means for moving the article endwise in the direction of the opening by a predetermined increment.

Means also are included for lowering: the article to substantially its original plane after it has been moved endwise, and for reapplying the lifting force at substantially the original point of application so that the article again may be moved endwise by the predetermined increment, this sequence being repeated until the article has been substantially fully introduced into the opening.

Considering the foregoing in greater detail and with particular reference to the drawings:

In the form of the invention illustrated in the drawings, the article handling system is applied to a fork truck of the class customarily employed for handling heavy articles such as stacks of plywood in a mill or warehouse. The fork truck is indicated generally at 10. It includes a body 12 containing the frame, motor and controls. Attached to the forward part of the body is the hoisting mechanism 14 which can be raised, lowered and tilted by the drive contained in the body in well known manner.

The apparatus of our invention is afiixed to the tilting portion 14 of such a fork truck. It includes a substantial frame indicated generally at 16. The frame includes a pair of end walls 18, 20, a top section 22, a longitudinally bored block 24 mounted on the top section, substantial rods 26 spanning the space between the side walls, upper and lower rub plates 28, 30 below and parallel to rods 26, and a central, vertical frame member 32 located substantially equidistant between side plates 18, 20.

Mounted on this frame are means for supporting and lifting the article to be handled, as well as for moving it in a direction transversely of the vehicle. The first mentioned means, ie the means for supporting and lifting the article include in the preferred form of the invention, a fluid operated cylinder, preferably a hydraulic cylinder 34, operating vertically, the piston rod of which is coupled by a pin and clevis 36 to the cross member 38 of a pair of spaced parallel, vertically disposed plates 40, 42. The lower ends of these plates are connected by means of pin 44 to the upper segment of an angularly bent fork member 46. This segment slides in a guide formed integrally with frame member 32.

The horizontal portion of fork member 46 is dimensioned suitably to underlie the central section of the load to be lifted. Reciprocation of the piston rod of cylinder 34 accordingly will move the fork between the dotted line positions of Fig. l, the load being lifted when the fork is raised, and deposited on load supporting members when the fork member is lowered.

The load supporting members are contained in an assembly driven by a fluid operated cylinder, preferably an hydraulic cylinder 48. This member is mounted in a horizontal position on top plate 22 of the frame. Its rearward end is pinned to a tab 50 on the frame; its forward end penetrates the bore through block 24.

The piston rod of cylinder 48 is coupled by means of pin and clevis 52 to a horizontally extendingtab 54 which extends inwardly from a substantial H-frame 56. The latter frame is mounted for lateral sliding reciprocation on rods 26 by means of slides 58, 60.

H-frame 56 carries a pair of forwardly extending, horizontal fork members 62, 64 which straddle the lifting fork member 46 and may be approximately equidistant therefrom. These fork members move laterally in response to the reciprocation of the piston rod of cylinder 48 by increments determined by the stroke of the rod.

Cylinders 34, 48 are included in a hydraulic system illustrated schematically in Fig. 2. A motor 70 drives a pump 72 which draws'fluid from areservoir 74. When cylinders .34, 48 are at rest this fluid passes through bypass valve 76 and returns to tank 74. However, if fourway valve 78 is operated, the fluid emergizes cylinder 34, and hence moves lifting fork 46 in the direction determined by the setting of the valve. correspondingly, when valve 80 is actuated, the supporting fork members 62, 64 are moved laterally in a direction determined by the valve setting.

Operation in operation, the herein described article handling apparatus may be employed in stacking 4 x 8 foot plywood or fiberboard panels in a warehouse filled with rows of stacks of such panels lining aisles which need be only slightly wider than the width of the lift truck and the load which it carries. The stacks are arranged at right angles to the aisles, and the space allotted to each stack need only be slightly greater than the width of the panels, e.g. only slightly greater than four feet.

A stack of plywood panels may be placed across forks 46, 62, 64 with fork 46 in lowered position. The truck is run down the aisle until the load on the forks is stationed opposite the opening in which it is to be inserted. If the opening is at a substantial distance from the floor, the entire handling apparatus mounted on frame 16 and including the forks may be elevated by means of the conventional hoisting attachment 14 carried by the truck.

Then Without turning or maneuvering the truck, the load of panels is ejected endwise by manipulation of the forks. First operation of cylinder 48 moves H-frame 56 and forks 62, 64 carried thereby, laterally by an increment determined by the length of stroke of the cylinder. Next, vertical cylinder 34 is actuated, elevating fork 46 to its upper dotted outline position. This lifts the stack of panels sufficiently to clear forks 62, 64 which thereupon are returned to their original position by operation of cylinder 48.

Next cylinder 34 is operated to return fork 46 to its lower position in which it is on a plane beneath the plane of forks 62, 64. Accordingly the weight of the load is carried entirely by these two forks, even though the load may sag in the middle because of its weight.

Cylinder 48 then is again actuated moving forks 62, 64 laterally to advance the panels endwise into the opening by another increment. This process is repeated as long as necessary to completely introduce the panels into the allotted space, the ends of the panels sliding either on the floor or on the upper panel of a'stack deposited previously so that they are not mutilated or damaged as they would be if they were to roll on rollers.

It is to be understood that the form of our invention herein shown and described is to be taken as a preferred example of the same and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of our invention or the scope of the subjoined claims.

Having thus described our invention, we claim:

1. Apparatus for stacking plywood panels and like articles which comprises a frame, a pair of spaced panelsupporting fork arms on the frame, adapted to support the panels, means connected to the supporting fork arms for reciprocating the same laterally, a lifting fork arm on the frame, and means for reciprocating the lifting fork arm independently of the panel supporting fork arms between a lower plane which is not above the plane of the supporting fork arm and an upper plane above the plane of the same and sufiicient to'lift the panels out of contact with the same.

2. The apparatus of claim 1 wherein the means for reciprocating the supporting fork arrn laterally and the lifting fork arm vertically comprise hydraulic cylinders.

3. Apparatus for stacking plywood panels and like articles which comprises a supporting frame, a vertical slide mounted centrally on the frame, an angularly bent lifting fork arm mounted in the slide, motor means connected to the lifting fork arm for reciprocating it vertically, a pair of spaced supporting fork arms straddling the lifting fork arm and mounted for lateral sliding movement of the frame, and second motor means connected to the supporting fork arms for reciprocating them in a horizontal plane intermediate the planes of the lifting fork arm whenin raised andlowered positions.

4. The apparatus 'of claim 3 wherein the motor means comprises fluid operated cylinders.

5. Apparatus comprising in combination with a lift truck including a hoisting mechanism: a frame carried by the hoisting mechanism, a vertical slide mounted centrally on the frame, an angularly bent lifting fork arm mounted in the slide, motor means connected to the lifting fork arm for reciprocating it vertically, a pair of spaced supporting fork arms straddling the lifting fork arm and mounted for lateral sliding movement on the frame, and second motor means connected to the supporting fork arms for reciprocating them in a horizontal plane intermediate theplanes of the lifting fork arm vlhen in raised and lowered positions.

6. Apparatus of claim 5 wherein the motor means comprise fluid operated cylinders.

7. Apparatus for moving a load into a storage opening comprising a frame, a lift arm on the frame adapted to engage the load, means connected to the lift arm for reciprocating it vertically, at least one support arm on the frame operable independently of the lift arm and adapted to support the load, and drive means connected to the support arm for reciprocating it laterally, whereby upon alternate engagement of the load by the lift arm and the support arm the load is adapted to be shifted laterally toward the opening.

8. Apparatus for moving a load into a storage opening comprising a frame load support means on the frame having lateral reciprocating movement, drive means for reciprocating the support means, lift means on the frame operable independently of the support means and having vertical reciprocating movement for raising the load onto and off the support means, drive means for reciprocating the lift means, and control means for alternately operating the drive means for the lift means and the drive means for the support means whereby the load is adapted to be alternately engaged by the support means and lift means to be shifted laterally toward the opening.

References Cited in the file of this patent UNITED STATES PATENTS 2,496,399 Lesser Feb. 7, 1950 2,628,734 Jannsen Feb. 17, 1953 2,713,432 Lorimer July 19, 1955 2,739,722 Joy Mar. 27, 1956 2,748,966 Gohrke June 5, 1956 

